Clam-digger



w. 0. COLLIER.

CLAM BIGGER.

APPLICATION FILED MAY 29, 1920.

1,387,590, Patented Aug. 16, 1921.

4 SHEETS-SHEET 1- I l 1 1 l l l gwwmtoz MAL/4M Q MM MW W. D. COLLIER.

CLAM DIGGER.

APPLICATION FILED MAY 29, I920.

1,387,590, Patented Aug. 16, 1921.

4 SHEETS-SHEET 2- W. D. COLLIER.

CLAM BIGGER.

APPLICATION FILED MAY 29, 1920.

Patented Aug. 16, 1921.

4 SHEETS-SHEET 3.

, WYHZOD IILJII W. D. COLLIER.

CLAM DIGGER.

APPUCATION FILED IAY 29. I920.

1,387,590. 7 Patented Aug. 16,1921.

4 SHEETS-SHEET 4.

v gwomtoc Mum/VD 6011/15? UNITED STATES WILLIAM D. COLLIER, OF MARCO, FLORIDA.

CLAIM-BIGGER.

Application filed May 29,

To all whom it may concern Be it known that I, WILLIAM D. COLLIER, citizen of the United States, residing at Marco, in the county of Lee and State of Florida, have invented certain new and useful Improvements in Clam-Diggers, of which the following is a specification.

This invention relates to clam diggers and is an improvement on the construction disclosed in my prior Patent No. 1,019,601, dated March 5, 1912.

In digging clams, it is the usual practice to employ an inclined endless conveyer or chain which is supported from a boat and projects downwardly to the bottom of the body of water, suitable clam digging mechanism being attached to the chains and adapted to lift the clams as the apparatus is operated. In order to effectually catch the clams in the diggers, it is necessary for the lower end of the clam digger to project below the bed of the stream into the mud. When the belt or chain is mounted on a pair of shafts and arranged at an incline, it is necessary for the lower end of the supporting framework and a portion of the digging mechanism to project into the mud and dirt. This causes considerable wear and increases the ditticulties of operation.

In the present invention, I have provided a construction wherein the lower endof the chain is arranged substantially vertical to decrease, as far as possible, the parts of the mechanism that are forced to come in contact with the bed of the stream and to ar range the clam diggers at the most effectual angle for digging the clams. The apparatus comprises a suitable frame-work hav ing a shaft mounted at the upper end, the conveyor chain passing around the shaft and being operably connected thereto by suitable means, such as sprocket wheels. At the bottom of the clam digger, apair of shafts 1s provided, one of which is so arranged that the belt or chain on its upward flight travels substantially parallel to the frame-work. The second shaft is arranged in the extreme lower portion of the frame-work and is so positioned with respect to the first mentioned lower shaft that a section of the belt or chain at the extreme lower end is arranged in a vertical plane. A second conveyer chain is arranged below the first mentioned chain substantially parallel thereto, and is adapted to serve as a support for the flights of the conveyer on the return trip.

Specification of Letters Patent.

Patented Aug. 16, 1921. 1920. Serial No. 335,207.

The lower end of this conveyor is so positioned that it causes the main conveyer to travel substantially parallel to the angle of the apparatus during the greater portion of ts return trip and then travel downwardly 1n a substantially vertical plane to the extreme lower shaft.

In the accompanying drawings, I have shown one embodiment of the invention. In this showing,

Figure 1 is a side elevation of the clam digger attached to a boat illustrating the method of operation.

Fig. 2 is an enlarged side elevation of the lower end of the clam digger.

Fig. 3 is a similar view of the upper end.

Fig. 4 is a transverse sectional view on the line H of Fig. 1.

Fig. 5 is an end elevation of the lower portion of the conveyer.

Fig. 6 is a transverse sectional view on the line 6-6 of Fig. 1, and

Fig. 7 is a detail view of the clam digger attached to the endless chain.

Referring to the drawings, the reference numeral 1 designates generally the boat to which the clam digger is attached. The device is adapted to be secured to the front end of the boat and pushed along the stream in which the clam bed is located. As shown, the clam digging apparatus comprises a pair of side boards 2 and 3 forming a suitable frame-work and it is provided with traction wheels 4 in the lower end adapted to travel along the bed of the stream. When the clam digger is in operative position, the framework is arranged at an angle or incline with the lower end resting on the body of the stream.

An upper shaft 5 is journaled in the frame-work and adapted to form the upper support of the endless conveyer or chain to which the clam digging elements are attached. A second shaft 6 is arranged near the lower end of the frame-work and positioned substantially the same distance from the top of the frame-work as the upper shaft. The extreme lower shaft 7 is journaled in the frame-work and is positioned so that it is in substantially the same vertical plane with the shaft 6 when the clam digger is attached to a boat at the proper angle. The conveyor comprises a pair of chains 8 and 9 which are adapted to travel over sprockets 10 on the upper shaft, sprockets 11 on the shaft 6, and sprockets 12 able source,

on the extreme lower shaft. Power is supplied to drive the apparatus from any suitand I have diagrammatically illustrated a pulley 13 on the upper shaft 5 whereby the apparatus is driven.

The lower flight of the conveyer travels downwardly the sprockets 10 and 11 cause the conveyer during its upward travel to follow a path substantially parallel to the angle of the entire apparatus, and the portion ofthe chain between the'sprockets-ll and 12 on the two lower shafts is in a substantially vertical plane. From the-inspection of Fig. 1 of the drawings, it will be apparent that it is necessary to provide meansfor supporting the lower or returning portion of the conveyer chain throughout ,its travel to maintain it parallel to the upper section, thereby preventing an unnecessary amount of the chain to contact with the river bed. As a means for sup porting the lower section of the chain, I en1 ploy a second or supporting conveyer properly. spaced below the first conveyer. The supportingconveyer consists of a pair of chains 14 and 15 passing over sprockets 1G and 17 arranged on shafts 18 and 19, the said shafts being arrangedin a plane substantially parallel to the plane of the shafts 5 and 6 whereby the supporting conveyer is maintained parallel to the main portion of the main conveyer. The supporting conveyer is: so positionedthat' the upper side of it forms a supportfor the lower side of the main conveyer and causes the lower side of themain conveyer to travel in a path substantially parallel to the path of travel of the upper side of the conveyer until it passes the lower end of the supporting conveyer. As shown in Figs. 1 and 2 of the drawings. the lower shaft'19 is so positioned that the chains ofthe main conveyer, after passing the sprocket 17, will travel downwardly in a substantially vertical plane to the sprockets 12 of the extreme lower shaft 7 of the main conveyer. To prevent sagging, a shaft 20 may be arranged near the middle of thesupporting conveyer and sprockets 21 mounted therein.

Referring to Fig. 7 of the drawings wherein the detail construction of the clam digging elements is shown, a pair of connecting plates 22 and 23 is secured to the two chains forming the upper conveyer and a second plate 24: having end flanges 25 and 26 issecured thereto. The end flanges are positioned inwardly from the ends of the plates 22 an'df23 to permit them to pass the sprockets of a lower conveyer as shown in Figs.'2'and'-3 of the drawings. A plurality of :diggers :26 is secured to the plate'24.

These diggers are curved to readily grasp the clams; an'd arerovided' with "slots 27 in 3 their" vertical port ons to permit "discharge of waterfa'n'd mud. In Fig. 7 of the drawings, I have illustrated only one of the diggers, but a plurality of these members are arranged on the plate 24: slightly spaced from each other, as shown in Fig. 4 of the drawings. It will be seen that when these elements are attached to the plate 24, the end flanges 25 and 26 cooperate therewith to form a three-sided scoop or bucket having the front end open. In actual operation, the best results are obtained by slightly spacing the clam digging elements longitudinally of the conveyer chain and it is best to employ cross plates 28 secured to the chains to prevent the clams from falling through the space between each pair of clam digging element-s. Any number of these plates 28 may be employed so spaced from eachother and the clamdigging elements that they will prevent the clams from falling through the spaces. 1

The supporting conveyer is driven from the shaft 5 of the main conveyer by means of suitable gearing. As shown, a gear 29 is mounted on the shaft 5 and this gear meshes with the second gear 30 mounted on the shaft 18' at the upper end of the supporting conveyer. It will be noted that the gearing arrangement drives the shafts of the two conveyers in opposite direction. However, the main conveyer, during its return. trip, contacts or engages the upper side of the supporting conveyer which is traveling downwardly inthe same direction as the lower side of the main conveyerl it is very advantageous to provide the gears '29 and 30 with the same number of teeth, whereby the two conveyers are revolved at the same speed. Referring to Fig. 6 of the drawings, it will be noted that the end plates 22 and 23'of the upper conveyer engage the chains 15 of the lower conveyer during the return flight of the upper conveyer and it is highly advantageous to have the two conveyers traveling at the same speed to eliminate surface friction.

The operation of this device will be apparent from an inspection of the drawings. When power is supplied to the shaft 5 through the drive connection '13, the main conveyer travels in the direction of the arrow in Fig. 1' of the drawings. \Vhen each of the clam digging elements reaches the bottom, it goes below the bed of clams and lifts them. The clams are then conveyed to the upper end of the apparatus and dumped into the boat. The arrangement whereby the lower end of the conveyer is in a substantially vertical plane eliminates scraping of unnecessary parts on the bed of the stream and thus reducing wear to a minimum. The apparatus can also be operated with less power than where the conveyer is mounted on one pair of shafts andtravels in a plane substantially parallel to the plane of the supporting frame-work. The lower sprocket plane with the wheel 17 of the supporting conveyer is so arranged that a tangent in the vertical plane will coincide with a tangent on the circle of the sprocket wheel 11, also drawn in the vertical plane whereby the extreme lower section of the conveyer chain on its return flight is also traveling vertically.

It is to be understood that while I have described the preferred embodiment of my invention, various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having described my invention, what I claim is:

l. A clam digger comprising an inclined frame, a plurality of shafts j'ournaled in said frame, an endless conveyer mounted on said shafts, two of said shafts being arranged to cause the conveyer to travel in a plane substantially parallel to the frame during the greater portion of its movement, a lower shaft disposed in the same vertical lower of said two shafts. whereby the conveyer is caused to travel in a vertical plane during a portion of its movement, digging elements secured to said conveyer, and means for supporting said conveyer during its return flight.

2. A clam digger comprising an inclined frame, a plurality of shafts journaled in said frame, an endless conveyer mounted on said shafts, two of said shafts being arranged to cause the conveyer to travel in a plane substantially parallel to the frame during the greater portion of its movement, a lower shaft disposed in the same vertical plane with the lower of said two shafts, whereby the conveyer is caused to travel in a vertical plane during a portion of its movement, digging elements secured to said conveyer, and means for supporting said conveyer during its return flight. said means being arranged to maintain the lower portion of the conveyer substantially parallel to the upper portion thereof.

8. A clam digger comprising an inclined frame. a plurality of shafts journaled in said frame. an endless conveyer mounted on said shafts, two of said shafts being arranged to cause the conveyer to travel in a plane substantially parallel to the frame during the greater portion of its movement, and a lower shaft disposed in the same vertical plane with the lower of said two shafts,

whereby the conveyer is caused to travel in a vertical plane during a portion of its movement, digging elements secured to said conveyer, and supporting means comprising a second conveyer adapted to support said first conveyor during its return flight.

a. A clam digger comprisin a frame, an endless conveyor, a plurality of shafts journaled in said frame and arranged to support said conveyer at an incline, an additional shaft arranged beneath the lower of said shafts and in substantially the same vertical plane to position the lower end of the conveyor in a vertical plane, clam digging elements secured to said conveyer, and means for supporting said conveyer during its return flight, said means being arranged to maintain the lower portion of the conveyer substantially parallel to the upper portion thereof.

5. A clam digger comprising a frame, an endless conveyor, a plurality of shafts journaled in said frame and arr: nged to support said conveyer at an incline, an additional shaft arranged beneath the lower of said shafts and in substantially the same vertical plane to position the lower end of the conveyer in a vertical plane, clam digging elements secured to said conveyer, and supporting means comprising a second convcyer adapted to support said first conveyor during its return flight.

A clam digger comprising a frame, an endless conveyer, a plurality of shafts journaled in said frame and arranged to support said conveyer at an incline, an additional shaft arranged beneath the lower of said shat ts and in substantially the same vertical plane to position the lower end of the conveyer in a vertical plane, clam digging elements secured to said conveyer, and a supporting conveyor arranged below said first conveyer and adapted to support said first conveyer during its return flight, said sumiorting conveyor being arranged on shafts in a plane substantially parallel to the plurality of shafts of the main conveyer, the lower shaft of said supporting conveyor being positioned with respect to said additional sha t of the main conveycr to cause the main conveyer to travel in a sulgistantially vertical plane during the last portion of its return flight.

In testimony whereof I alhx my signature.

WILLIAM D. COLLIER. 

